Dielectric sleeve for electrically and mechanically protecting exposed female contacts of an electrical connector

ABSTRACT

An electrical connector assembly of the type having a plurality of male pin-type contacts that mate with a plurality of female socket-type contacts that includes a dielectric sleeve mounted around the exposed portion of each of the female contacts. The dielectric sleeve reinforces the mechanical strength of the female contacts, protects the female contacts from damage, prevents &#39;&#39;&#39;&#39;flashover&#39;&#39;&#39;&#39; between female contacts that would occur because of the closer spacing between the female contacts than the male contacts, and prevents mating of the female contacts with oversized male pin-type contacts.

United States Patent [1 1 Normann Oct. 29, 1974 I 1 DIELECTRIC SLEEVEFOR ELECTRICALLY AND MECHANICALLY PROTECTING EXPOSED FEMALE CONTACTS OFAN ELECTRICAL CONNECTOR Richard W. Normann, Otego, NY.

The Bendix Corporation, Southfield, Mich.

Filed: Feb. 27, 1973 Appl. No.: 336,309

Inventor:

Assignee:

US. Cl. 339/191 R, 339/59 R, 339/213 R Int. Cl H011 19/28 Field ofSearch, 339/59, 191-193,

References Cited UNITED STATES PATENTS l/1916 Pearl et a1 339/196RX3/1958 Rhodes 339/75 M X 2/1961 Colwell 339/213 R X 10/1961 Purinton339/258 R X 3,059,208 10/1962 Concelman 339/213 R X 3,377,613 4/1968Archer 339/191 R X FOREIGN PATENTS OR APPLICATIONS 110,047 5/1925Switzerland 339/192 R Primary Examiner-Roy D. Frazier AssistantExaminer-Lawrence J. Staab Attorney, Agent, or Firm-Raymond J. Eifler [57 ABSTRACT 3 Claims, 4 Drawing Figures own 1 BEST EVAILABLE COPYDIELECTRIC SLEEVE FOR ELECTRICALLY AND MECHANICALLY PROTECTING EXPOSEDFEMALE CONTACTS OF AN ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTIONThis invention relates to multipin electrical connectors of the typehaving male pin-type contacts that mate with female socket-type contactsin the other half of the connector assembly. This invention is moreparticularly related to a dielectric sleeve that is mounted on thefemale socket contact to improve the electrical performance of theconnector.

In pin and socket-type multipin electrical connectors, the breakdownvoltage between adjacent contacts, i.e., the disruptive dischargethrough air between two adjacent contacts of different potential, is afunction of the distance between the two adjacent surfaces. It should bereadily appreciated that female socket contacts, arranged and spaced tomate with similarly arranged male contacts having a smaller diameter,will have a breakdown or flashover voltage that is lower than thatassociated with the male contacts. In any electrical connector, thevoltage rating is determined by the weakest link in the chain andtherefore the voltage rat ing of the connector generally does not exceedthe voltage at which flashover or breakdown occurs between two femalecontacts. Further, socket-type female contacts are subject to mismatingwith connector elements that contain pin-type male contacts that aresized for mating with larger sized sockets. Mis'mating causes thesockets to be expanded so that in subsequent matings with properly sizedcontacts poor or intermittent electrical contact is established betweenthe mechanically mated male and female contacts.

SUMMARY OF THE INVENTION This invention provides an electrical connectorassembly wherein the breakdown voltage between two adjacent femalecontacts is greater than the breakdown voltage between two adjacent malecontacts. The invention further provides a means for improving theelectrical performance of all multipin pin and sockettype electricalconnectors and to prevent mismating of the socket contact with oversizedmale pin contacts.

The invention is an electrical connector assembly characterized by anelectrical connector element that includes a dielectric sleeve (30)mounted on and surrounding the mating portion of the female socketcontacts which may be removably or fixably mounted in a connector insertThe opening (31) in the sleeve (30) is sized to receive male contacts(100) not exceeding a predetermined diameter.

In one embodiment of the invention, an electrical connector thataccomplishes the objects of the invention comprises: a first assemblyhaving an insert (200), a plurality of bores arranged in a predeterminedspaced relationship in the insert (200), and a plurality of malecontacts (100), each disposed in one of the bores; and a second assemblyseparably connectable to the first assembly, the second assemblyincluding an insert (20) having a front face (21) and a rear face. aplurality of bores through the second assembly insert (20) from thefront face (21) to the rear face, the bores arranged in the same spacedrelationship as the bores in the first assembly insert so that when thefirst and second assemblies are connected together, the axis of thebores in the first insert are aligned with the axis of the bores in thesecond insert; a plurality of female contacts (10), each mounted in oneof the bores of the second insert (20), each of the female contacts (10)having a resiliently expandable mating portion (14) that extends out ofthe second insert (20) from the forward face and a groove (12) in theforward portion of the female contact (10); and a sleeve (30) comprisedof insulating material mounted on each of the female contacts (I0), theinsulating sleeve (30) surrounding the mating end (14) of the femalecontact (10) that extends from the front face (21) of the insert (20),the sleeve (30) including an internal annular shoulder (32) that engagesthe groove (12) in the female contact (10) to maintain the insulatingsleeve (30) in a fixed mounted position around the contact mating end(14) and an opening (31) in the mating end (14) of the -sleeve (30)sized to receive male pin-type contacts not exceeding a certainpredetermined diameter.

Accordingly, it is an object of this invention to provide that portionof an elecrical connector assembly that contains the female socketcontact elements with means for preventing electrical breakdown betweenadjacent contacts.

It is another object of this invention to provide a sleeve thatreinforces the strength of a female socket contact, protects the femalesocket contact from damage, and provides electrical isolation betweenadjacent BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectionaldiagrammatic view of a mateable electrical connector assembly thatembodies the principles of this invention.

' FIG. 2 illustrates a plan view of a female socket type electricalcontact.

FIG. 3 illustrates a cut-away view of a dielectric sleeve used toaccomplish the objects of this invention.

FIG. 4 illustrates a side view of the socket contact shown in FIG. 2illustrating the shape of the female contact.

DETAILED DESCRIPTION OF THE DRAWINGS 1 Referring now to the drawings,FIG. 1 illustrates portions of a mateable electrical connector assemblythat embodies the principles of this invention. The first half (1) ofthe connector assembly includes a plurality of male pin-type contacts(100) that arranged in a predetermined spaced relationship in aninsert.(200). The forward end of the male contacts (100) are adapted tomate with socket-type female contacts.

The second half (2) of the connector assembly that is mateable in aseparable manner to the first half (1) of the connector assemblyincludes a dielectric insert (20); a plurality of contacts (10) mountedin the di-' electric assembly (20); and a plurality of sleeves (30),comprised of an electrically nonconducting material, mounted on each ofthe female electrical contacts The insert includes a forward face (21from which the forward portion of the electrical contact (10) extends toreceive and mate with the forward portion of the male pin-type contacts(100). Each of the female contacts (10) includes an enlarged portion(11) that secures the contact (10) within the insert (20). The forwardportion of the contact (10) includes a male contact receiving portion ormating portion (14) that further includes one or more axial slots (13)so that the forward mating portion (14) of the contact (10) isresiliently expandable radially so as to provide pressure contactbetween the mating end (14) of the female socket-type contact (10) andthe pin portion of the male contact (100).

The dielectric or insulating sleeve (30) is mounted on the forwardportion of the female contact (10) so as to surround the portion of thefemale contact (10) that extends beyond the first face (21) of theinsert (20). The dielectric sleeve may be comprised of teflon, nylon,thermoplastic or a thermosetting plastic so that the sleeve (30) may betelescopically mounted on the female contact (10) and held in placeeither by pressure contact or by some other suitable means. The rigidityof the sleeve (30) protects the female contacts (10) from damage due toblows or inadvertent engagement with noncontact members. Further, thedielectric sleeve (30) reinforces the strength of the socket contact(10) and provides electrical isolation between the contacts over thatportion of the contact (10) that is not surrounded by the insert (20).Additional features of the dielectric sleeve (30) includes an opening(31) that is sized to receive a contact that does not have a diametergreater than a predetermined dimension. Therefore, the opening (31)prevents damage to the female contacts (10) by preventing engagement ofthe female contact 10) with noncontact type members and/or male pin-typecontacts that are oversized and should not be inserted into the femalecontacts (10). Obviously, mismating of socket-type female contacts (10)with oversized male pin-type contacts can either break the mating endportions (14) of the female contact that are located between axial slots(13) and/or deflect this divergent portion of the mating end (14) sothat subsequent mating with correct sized male contacts causeintermittent electrical signals between the male and female contactsbecause there is no physical contact or insufficient pressurized contactbetween the male and female contacts.

FIG. 2 illustrates a female socket-type electrical contact (10) thatincludes a means (12) for securing a sleeve (30, FIG. 1) to theelectrical contact (10). The electrical contact (10) includes anenlarged portion (11 that permits the electrical contact to be fixedlyor removably mounted with a connector insert. The axial slots (13) inthe mating portion (14) of the contact (10) defines a plurality offingers that extend radially inwardly with respect to the axis of thesocket to make the forward mating portion (14) of the contact (10)resiliently expandable so that when a pin-type contact (100) is insertedinto the mating end (14) of the contact (10), the male and femalecontacts are in pressurized contact. To more securely fasten the sleeve(30, FIG. 1) to the contact (10), the contact (10) includes an annulargroove (12) for receiving an internal shoulder in the sleeve (30, FIG.3).

FIG. 3 illustrates a cut-away view of the dielectric sleeve (30) thataccomplishes the objects of the invention when used in combination withan electrical connector of the type shown in FIG. 1. The sleeve (30)includes a male contact receiving end portion that has an inwardlytapered opening (35) for guiding a male pin (not shown) into the opening(31) which further guides the male pin into the female socket-typecontacts (10, FIG. 1). Although the sleeve (30) may be mounted on acontact (10) and held in place by pressurized contact, it is preferredthat the sleeves (30) have an internal annular shoulder (32) that mateswith and/or engages the groove (12) of the contact shown in FIG. 1.Preferably, the sleeve is comprised of plastic which allows the shoulder(32) to resiliently deform as the sleeve (30) is telescopically movedinto position on the female contact (10) when the internal shoulder (32)of the sleeve (30) reaches the groove (12) in the contact (10), anaudible snap is heard that notifies the assembler that the sleeve is nowproperly in place on the contact. Referring again to FIG. 1, it can beseen that the sleeves (30) electrically isolates each of the femalecontacts (10), one from another. FIG. 4 is a side view of FIG. 2 thatillustrates the shape of the contact and the location of the axial slots(13). v

While a preferred embodiment of the invention has been disclosed, itwill be apparent to those skilled in the art that changes may be made tothe invention as set forth in the appended claims and, in someinstances, certain features of the invention may be used to advantagewithout corresponding use of other features. For example, .although thedielectric sleeves (30) are shown to be snapped in the contact (10), thesleeve (30) may be cemented or bonded with adhesive to the contact (10).Accordingly, it is intended that the illustrative and descriptivematerials herein be used to illustrate the principles of the inventionand not to limit the scope thereof.

Having described the invention, what is claimed is:

1. In combination with an electrical connector element of the typehaving an insert and a plurality of female contacts mounted therein withthe mating end of the female contact extending from one face of saidinsert, each of said female contacts including an enlarged portion and aforward portion that includes the mating end and an annular groovehaving a rearwardly facing shoulder in the forward portion of thecontact, the improvement comprising:

a plurality of sleeves comprised of electrically insulating material,each mounted on the forward portion of one of said female contacts andcompletely surrounding said mating portion of said contacts, each ofsaid sleeves including an internal projection having a forwardly facingshoulder that mates with the annular groove in said female contact andengages the rearwardly facing shoulder of said groove to secure thedielectric sleeve to the forward portion of said female contact andwherein each of said sleeves includes a forward male contact receivingend portion that tapers radially inward with respect to the axis of saidsleeve from free end so as to provide a means for guiding a male contactinto said sleeve and said mating portion of said female contact.

6 2. The connector element as recited in claim 1 mits the resilientdeformation of said internal shoulder wherein said sleeve is comprisedof plastic. on said sleeve when said sleeve is telescopically 3. Theconnector element as recited in claim I mounted on said female contact.wherein said sleeve is comprised ofamaterial that per-

1. In combination with an electrical connector element of the typehaving an insert and a plurality of female contacts mounted therein withthe mating end of the female contact extending from one face of saidinsert, each of said female contacts including an enlarged portion and aforward portion that includes the mating end and an annular groovehaving a rearwardly facing shoulder in the forward portion of thecontact, the improvement comprising: a plurality of sleeves comprised ofelectrically insulating material, each mounted on the forward portion ofone of said female contacts and completely surrounding said matingportion of said contacts, each of said sleeves including an internalprojection having a forwardly facing shoulder that mates with theannular groove in said female contact and engages the rearwardly facingshoulder of said groove to secure the dielectric sleeve to the forwardportion of said female contact and wherein each of said sleeves includesa forward male contact receiving end portion that tapers radially inwardwith respect to the axis of said sleeve from free end so as to provide ameans for guiding a male contact into said sleeve and said matingportion of said female contact.
 2. The connector element as recited inclaim 1 wherein said sleeve is comprised of plastic.
 3. The connectorelement as recited in claim 1 wherein said sleeve is comprised of amaterial that permits the resilient deformation of said internalshoulder on said sleeve when said sleeve is telescopically mounted onsaid female contact.